Stimulated by a rising interest in the D-Band in research and industry, the demand for accessible measurement equipment is increasing. As the frequency range of vector network analyzers (VNAs) is insufficient, vector network analyzer extension (VNAX) modules are needed. Commercially available options consist of discrete components, which increases the size and price of such modules. Therefore, in this work, we present a VNAX module, which combines most of the functions on a single SiGe-MMIC. To demonstrate its functionality, we compare it to a state-of-the-art VNAX module in a two-port WR 4.3 waveguide measurement. Additionally, we present a maximum system and receiver dynamic range of 75 dB and 129 dB at a resolution bandwidth of 10 Hz. To address potential temperature concerns of our approach, the achieved phase- and magnitude stability is typically in a range of ?0.2 dB and ?1 degree for the time span of one hour.